Re: A7N266-VM : Geforce 2 MX Onboard : Freeze at NVIDIA Logo
nvidia-installer removes all parts of the driver which are installed via nvidia-installer. However, if you're using Ubuntu, you've got bits of the driver elsewhere, and they will not get removed (or more precisely, will get reinstalled every time you reboot). This is a Ubuntu bug which has been documented in the forum sticky posts (as well as many other threads on this forum).
About the only thing that I can blindly suggest for your instability, is to set NvAGP to 0 in xorg.conf. Until you can attach a bug report that actually reflects the configuration that you are running, I can't comment further.